jagged 1
A gene that codes for a protein called jagged 1. The jagged 1 protein binds to notch proteins that are receptors on the surfaces of certain cells. The formation of the jagged 1–notch complex sets in motion a series of signaling reactions that controls the development of various cell types in an embryo, including the heart, liver, eyes, ears, spinal column, and blood cells. Certain mutations in JAG1 can cause Alagille syndrome, which is characterized by missing or narrowed bile ducts in the liver, heart defects, and characteristic facial features. Other mutations in JAG1 result in various other abnormalities, including a heart defect called Tetralogy of Fallot, deafness, and a liver condition called extrahepatic biliary atresia (EHBA). The JAG1 gene is located on chromosome 20 at gene map locus p12.1-11.23.